NED Abstract

Copyright by American Astronomical Society.
Reproduced by permission
1990ApJ...354...52D
THE CORRELATION OF X-RAY AND OPTICAL LUMINOSITIES OF EARLY-TYPE GALAXIES
USING NEW DATA AND DISTANCES
R. HANK DONNELLY, S. M. FABER, AND R. M. O'CONNELL
University of California Observatories/Lick Observatory Board of Studies
in Astronomy and Astrophysics, University of California at Santa Cruz
Received 1989 June 16; accepted 1989 October 30
ABSTRACT
Using new apparent magnitudes and new distances as determined from the
D_n_^-{sigma}^ method, we have reexamined the correlation of X-ray to
optical luminosities for E and S0 galaxies. The residuals about our least-
squares fits decline significantly but are not removed altogether. All
attempts to correlate the remaining residuals with other structural and
spectral parameters have given negative results, suggesting that some
other, as yet unidentified, factor plays a role in defining X-ray
luminosity with respect to optical luminosity. L_x_ versus L_B_ also
appears to be a useful secondary distance indicator for early-type
galaxies.
Subject headings: galaxies: distances - galaxies: photometry - galaxies: X-
rays